I've just bought star69 very nicely done 1675 which has the DG movement . From the research
I did the majority opinion is to use a josh 1655 case and get it re shaped. I have used phong case sets for both 1665 and 1655 Franken builds and while they are,in my opinion the best available in terms of correct serial numbers your looking at 1,500 usd a pop. By the Time you put in a correct 1575 movement(not a badly modded 1570,be very careful!) 2,600 usd for one. you'd be better buying a gen